Knee brace with flexible secondary joint

Abstract

There is provided a knee brace having a primary joint and a flexible secondary joint. The brace permits a more natural flexibility of the knee and lower leg, both when the lower leg is co-linear with the upper leg and when the lower leg is bent relative to the upper leg, as in the case during the sitting.

Having thus described my invention, what I claim as new, useful, and non-obvious and, accordingly, secure by Letters Patent of the United States is: 
     
       1. A knee brace having a primary joint and a flexible secondary joint, the brace comprising: (a) an upper member for the support of a lateral side of a leg above the knee thereof, said upper member having an upper end and a lower end;   (b) a lower means for the support of said lateral side of the leg below the knee thereof, said lower member having an upper end and a lower end;   (c) a bi-axial element having a primary axis and a second axis, said lower end of said upper member being rotationally coupled to said primary axis, said upper end of said lower member being rotationally coupled to said secondary axis;   (d) lock means for selectively locking said lower end of said upper member to said primary axis, thereby selectably overriding said rotational coupling between said upper member and said primary axis of said bi-axial element, in which actuation of said locking means operates to change the effective axis of said bi-axial element from said primary axis to said second axis; and   (e) mechanical damping means oriented in said bi-axial element and applied against said secondary axis, said damping means comprising means for angularly biasing said secondary axis relative to said primary axis in a direction of rotation anterior to said primary axis,   whereby said knee brace will permit a more natural flexibility of the knee and of the lower leg, both when the knee is straight and when the knee is bent as is the case during sitting.   
     
     
       2. The system as recited in claim 1, which said mechanical damping means comprises: a pair of compression-adjustable spring assemblies each positioned to apply its spring force in the same direction as the direction of the rotation of said secondary axis, but to apply the spring force of said spring assemblies in opposing directions relative to the plane of a radius of rotation of said secondary axis.   
     
     
       3. The brace as recited in claim 2, in which said lock means comprises a slip element proportioned to peripherally engage both said lower end of said upper member and said primary axis of said bi-axial element. 
     
     
       4. The brace as recited in claim 3, in which said damping means comprising springs and ball bearings said bearings, comprising interface means between an inner end of each said springs and said upper end of said lower member. 
     
     
       5. The brace as recited in claim 4, in which said spring assemblies comprise Allen-head screw nuts at both outer ends of said spring assemblies wherein upon the rotational advancement of said Allen-head screw nuts, an increase of the compression of the springs of said spring assemblies will occur.